1. Field of the Invention
The invention is related to apparatus for continuously conveying and simultaneously turning objects of arbitrary shape and size and, more specifically, to apparatus of this type with an object conveying and turning trough of which at least a bottom portion is formed by a rotating roller.
2. Prior Art
Workpieces or parts, the surface of which is to be uniformly treated on all sides, such as for the purpose of cleaning or coating, or for surface finishing with abrasive material jets, have to be fed to the processing operation in such a manner that they are continuously moved onward in the processing zone and are simultaneously revolved or turned according to their shape.
From Swiss Patent 535,693 an apparatus of the initially mentioned type has become known for a jet treatment of objects, wherein the objects through their own weight depress resilient bristles or lamina disposed on rollers and, during rotation of the rollers, are propelled through succeeding bristles or lamina which are tilted in the direction of propulsion. The linear propulsion of the workpieces thus depends on the relationship of the weight of the workpiece to the elasticity of the bristles or lamina. Relatively light bodies or objects do not depress the bristles or lamina, while relatively heavy bodies cannot be moved on by the succeeding bristles or lamina. Bodies or objects of an unfavorable or irregular shape are unsuitable for transport in such prior-art apparatus. Also, small, light workpieces with holes or eyelets tend to get caught up in the bristles. Finally, the wear of the bristles or lamina due to heating and abrasion is relatively high because of the necessity to make the bristles or lamina of an elastic material. Moreover, the employment of such apparatus in jet-type machines, where jets of hard, abrasive materials are used, is inappropriate, since these jets would destroy the bristles or lamina in a short time.
Another known apparatus employs two rollers arranged side-by-side rotating in the same sense. Arranged below these rollers is a chain which by means of cams reaches between the rollers into the conveyor track and takes care of the advance of the workpieces rotating between the two rollers. It is evident that this apparatus can only be utilized for relatively rugged workpieces of substantially cylindrical shape.